The present invention disclosed herein relates to a processor, and more particularly, to an embedded processor that consumes low power.
A processor can be classified into a single chip processor such as a central processing unit (CPU) used in a personal computer and an embedded processor used as a configuration block in a system on chip (SoC) such as various control chips or smart card chips. The embedded processor (e.g., MPU/MCU/DSP) is extensively used in a variety of operations and signal processing. In general, the embedded processor fetches, decodes, and executes an instruction. The embedded processor performs a series of processes such as processing a signal, reading the processed signal, and writing the processed signal. The highly functionalized embedded processor has increased power consumption and heat dissipation because the degree of integration is improved.
Energy efficiency is defined by performance/total power.
A unit of energy efficiency is MIPS/mW or millions of operations per second (MOPS)/mW. Millions Instruction Per Second (MIPS) is a typical unit indicating performance, and means that millions of instructions can be processed per second. While comparing with the above reference, if performance of the embedded processor is enhanced and power consumption is reduced, the embedded processor can achieve high energy efficiency.
In general, power consumption is proportional to the square of applied power voltage. Although decreasing of power voltage is the most effective way of reducing power consumption, low power voltage increases delay time. That is, the performance of a processor can be deteriorated.